The proposed program will allow the candidate the opportunity to enhance his research capabilities in the area of hypertension. The proposed research examines the interaction between hypertension and sexual behavior. The male rat is an important model in which to study hypertension and the neuroendocrine bases of reproductive function, including sexuality. Several hypotheses are examined: [1] that genetic hypertension adversely affects sexual function and behavior; [2] that sexual dysfunction in the spontaneously hypertensive rat is related to hypertension per se and not to other factors; [3] that the nature/degree of sexual dysfunction is related to the etiology of the hypertension; and [4] that hypertension can be alleviated by pharmacological treatment without compromising sexual function. For the first two hypotheses, spontaneously hypertensive rats will be used, for the third hypothesis hypertension will be induced in Long-Evans rats by either unilateral constriction of the renal artery, or by treatment with deoxycorticosterone. Hypothesis four will utilize the three experimental models. Sexual reflexes, as well as various of the parameters of copulatory behavior indicative of sexual motivation and potency will be evaluated concomitantly with blood pressure. At the conclusion of each experiment, the reproductive neuroendocrine status will be evaluated by measuring circulating levels of pituitary-gonadal hormones and reproductive organ weights. To evaluate the involvement of the renovascular system, plasma renin activity will be determined and kidney and heart weights obtained. These studies will contribute to our understanding of the relationship between hypertension and sexual function.